Known to the art are proximity sensors for parking areas, which are designed to detect the presence/absence of a vehicle parked in a delimited area (stall, generally of a rectangular shape).
For example, known to the art are sensors that use magnetic components (normally inductors), made in the ground and designed to interact magnetically with the metal mass constituted by the vehicle, in order to detect the presence of the vehicle itself.
For example, the Italian patent application No. GE2004A000053 filed on Jun. 16, 2004 describes a sensor of the type illustrated above that uses magnetometric sensors designed to detect the perturbation of the Earth's magnetic field introduced by the presence of the metal mass of the vehicle. Said magnetometric sensors communicate with a central processing station by means of a wireless network.
It has moreover been proposed to use radar for detecting the presence/absence of vehicles in a parking area.
For example, the U.S. Pat. No. 5,777,951 generically describes the use of a radar sensor for detecting the presence/absence of a vehicle.
In actual fact the use of a radar sensor for detecting the presence/absence of a vehicle is a not immediately implementable function in so far as radars are configured for detecting generically the position of an object in space with respect to a reference and involve complex processing (in the frequency domain) of the signals received.
Consequently, it is currently not possible to use, with contained costs, radar sensors for determining the presence/absence of a vehicle in a parking area.